Hubble Space Telescope spots fifth moon orbiting Pluto

Pluto may no longer be able to roll with the big boys, but that isn't stopping NASA scientists from continuing to take an interest in it. As it turns out, the Hubble Space Telescope has discovered a fifth moon orbiting the solar system's second-most-massive dwarf planet. P5, as it's being called, is an irregularly shaped moon that's 6 to 15 miles across and whips around Pluto in a 56,000-mile-diameter circular orbit.

P5 was discovered as NASA's Pluto team used the Hubble Space Telescope to scan the area surrounding the planet for debris or anything else (like undiscovered moons, perhaps?) that may damage or destroy NASA's New Horizons spacecraft as it flies through the Pluto system in 2015. NASA says that with New Horizons travelling at 30,000 miles per hour, the spacecraft could be destroyed by a piece of debris the size of a BB. "The discovery of so many small moons indirectly tells us that there must be lots of small particles lurking unseen in the Pluto system," says Harold Weaver of the Johns Hopkins University Applied Physics Laboratory.

Indeed, as strange as it may seem, NASA scientists are discovering moons orbiting Pluto at something of an alarming rate. It was only last year that P4 was discovered, and before that came the discovery of Nix and Hyrda in 2006. Up until that point, we thought that the only moon orbiting Pluto was Charon, which was discovered back in 1978.

As for how P5 came into existence, the Pluto team thinks that it was formed when Pluto collided with another celestial body billions of years ago, much in the same way scientists believe our own moon was formed. Take a look at our story timeline below for more interesting stories from space!